Adaptive streaming for lightfield or holographic media

ABSTRACT

Method, device, and non-transitory storage medium for adaptive streaming of immersive media are provided. The method may include determining characteristics associated with a scene to be transmitted to the end client, adjusting at least a part of the scene to be transmitted to the end client based on the determined characteristics, and transmitting an adaptive stream of the lightfield or holographic immersive media comprising the adjusted scene based on the determined characteristics.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority from U.S. Provisional Pat. ApplicationNo. 63/270,978, filed on Oct. 22, 2021, in the United States Patent andTrademark Office, the disclosure of which is incorporated herein byreference in its entirety.

FIELD

Embodiments of the present disclosure relate to image and video codingtechnologies. More specifically, embodiments of the present disclosurerelate to improvements in adaptive streaming of immersive media contentfor holographic display or lightfield displays.

BACKGROUND

Immersive media relates to immersive technologies that attempt to createor imitate the physical world through digital simulation, oftensimulating any or all human sensory systems to create the perceptionthat the user is physically present inside a scene.

Immersive media technologies may include Virtual Reality (VR), AugmentedReality (AR), Mixed Reality (MR), Light Field/Holographic, etc. VRrefers to a digital environment replacing the user’s physicalenvironment by using a headset to place the user in a computer-generatedworld. AR takes digital media and layers them on the real world aroundyou by using either a clear vision or a smartphone. MR refers toblending the real world with the digital world, creating an environmentwhere technology and the physical world can co-exist.

Lightfield display or Holographic display technologies consist of lightrays in 3D space with rays coming from each point and direction. Lightrays may be five-dimensional plenoptic functions, where each beam may bedefined by three coordinates in 3D space (3 dimensions) and two anglesto specify the direction in 3D space. The concept of lightfield displaysis based on the understanding that everything seen around is illuminatedby light coming from any source, traveling via space and hitting thesurface of the object where the light is partly absorbed and partlyreflected to another surface before reaching our eyes. What exact lightrays reach our eyes depends on the user’s precise position in the lightfield, and as the user moves around, the user perceives part of thelight field and uses that to get an idea about the object’s position.

To capture the content for 360-degree video, a 360-degree camera isrequired; however, when it comes to capturing content forlightfield/holographic displays, an expensive setup comprising ofmultiple depth cameras or an array of cameras is required depending onthe FoV of the scene to be rendered. A traditional camera can onlycapture a 2D representation of the light rays that reach the camera lensat a given position. The image sensor records the sum of the brightnessand color of all light rays reaching each pixel but not the direction ofall light rays reaching the camera sensors. Thus, devices specificallydesigned to capture content for lightfield/holographic displays are costprohibitive.

Furthermore, the multimedia content, real-world content or syntheticcontent, for such holographic displays or lightfield displays has a hugesize and is captured and stored in a server. To transmit this mediacontent over to the end client requires a massive amount of bandwidtheven after the data is compressed. Therefore, in situations when thebandwidth is limited, the client may experience buffering orinterruptions.

SUMMARY

According to embodiments, a method for adaptive streaming of lightfieldor holographic immersive media may be provided. The method may beexecuted by at least one processor an may include determiningcharacteristics associated with a scene to be transmitted to an endclient, based on the determined characteristics adjusting at least apart of the scene to be transmitted to the end client; and transmittingan adaptive stream of the lightfield or holographic immersive mediacomprising the adjusted scene based on the determined characteristics.

According to embodiments, an apparatus for adaptive streaming oflightfield or holographic immersive media may be provided. The apparatusmay include at least one memory configured to store program code; and atleast one processor configured to read the program code and operate asinstructed by the program code. The program code may first determiningcode configured to cause the at least one processor to determinecharacteristics associated with a scene to be transmitted to an endclient; second determining code configured to cause the at least oneprocessor to adjust at least a part of the scene to be transmitted tothe end client based on the determined characteristics; and transmittingcode configured to cause the at least one processor to transmit anadaptive stream of the lightfield or holographic immersive mediacomprising the adjusted scene based on the determined characteristics.

According to embodiments, a non-transitory computer-readable mediumstoring instructions may be provided. The instructions, when executed byat least one processor of a device for adaptive streaming of lightfieldor holographic immersive media may cause the at least one processor todetermine characteristics associated with a scene to be transmitted toan end client; based on the determined characteristics associated withthe end client, adjust at least a part of the scene to be transmitted tothe end client; and transmit an adaptive stream of the lightfield orholographic immersive media comprising the adjusted scene based on thedetermined characteristics.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a depth-based adaptive streaming of immersive media,according to an embodiment of the present disclosure.

FIG. 2 illustrates a priority-based adaptive streaming of immersivemedia, according to an embodiment of the present disclosure.

FIG. 3A illustrates a flowchart for adaptive streaming of immersivemedia, according to an embodiment of the present disclosure.

FIG. 3B illustrates a flowchart for adaptive streaming of immersivemedia, according to an embodiment of the present disclosure.

FIG. 4 is a simplified block diagram of a communication system,according to an embodiment of the present disclosure.

FIG. 5 is a diagram of the placement of a video encoder and decoder in astreaming environment.

FIG. 6 is a functional block diagram of a video decoder, according to anembodiment of the present disclosure.

FIG. 7 is a functional block diagram of a video encoder, according to anembodiment of the present disclosure.

FIG. 8 is a diagram of a computer system, according to an embodiment ofthe present disclosure.

DETAILED DESCRIPTION

Aspects of the disclosed embodiments may be used separately or incombination. Embodiments of the present disclosure relate toimprovements in adaptive streaming technologies for immersive lightfieldor holographic media streaming that take cognizance of the networkand/or device capabilities.

Holographic/light field technology creates a virtual environment with anaccurate sense of depth and three-dimensionality without the need to useany headset and therefore avoid side effects like motion sickness. Asstated above, to capture the content for 360-degree video, a 360-degreecamera is required; however, when it comes to capturing content forlightfield or holographic displays, an expensive setup comprising ofmultiple depth cameras or an array of cameras is required depending onthe field of view (FoV) of the scene being captured.

According to an aspect of the present disclosure, a server or a mediadistribution processor may use depth-based adaptive streaming forholographic or lightfield display media. In instances of low networkbandwidth or low processing capacity instead of rendering the entirescene at once, a bandwidth-based depth approach is disclosed. When thenetwork’s capacity is ideal, the end client may receive and render theentire scene at once. However, when network bandwidth or processingcapacity is limited, the end client, instead of rendering the entirescene, renders the scene to a certain depth. Thus, according to anembodiment, depth is a function of the client’s bandwidth. Inembodiments, after getting information about the end client’s bandwidth,the server adjusts the media being streamed between scenes with varyingdepth.

Referring to FIG. 1 , FIG. 1 illustrates a depth-based approach 100 foradaptively streaming media associated with holographic or lightfielddisplay. As shown in FIG. 1 , objects 101-103 are one or more objects inthe scene at varying depths, with object 101 being at a first depth 105,object 102 at a second depth 106, and object 103 at a third depth froman imaging device (also referred to as camera or capture device).According to embodiments of the present disclosure, based on the networkbandwidth or the processing capability of the end client, only objectsup to the first, the second, or the third depth may be included. In someembodiments, if only objects up to a second depth are to be included,the objects at the third depth may be excluded from the scene beingtransmitted or streamed.

According to embodiments, depth-based streaming is superior todelivering the entire scene at once since the scene depth may beadjusted based on the available network bandwidth as opposed tobuffering or interruption in playback that can happen when the client’sbandwidth is limited and can’t support rendering the entire scene.

According to an aspect of the present disclosure, the server may assigna priority value to each asset (also referred to as object) and use thispriority value for adaptive streaming the holographic or lightfielddisplay. Thus, a bandwidth-based priority approach is considered so thatinstead of rendering the entire scene at once, only a prioritizedversion of the scene is transmitted and rendered. When the network’scapacity is not limited, the end client can receive and render theentire scene assets at once. However, when network bandwidth orprocessing capacity is limited, the end client may render assets withhigher priority instead of rendering all assets in a scene. Therefore,the total assets and/or objects rendered are a function of the client’sbandwidth. According to an embodiment, after getting information aboutthe end client’s bandwidth, the server adjusts the media being streamedbetween scenes with varying assets.

Referring to FIG. 2 , FIG. 2 illustrates a priority-based approach 200for adaptively streaming media associated with holographic or lightfielddisplay. As shown in FIG. 2 , objects 201-203 are one or more objects inthe scene at varying depths and priorities, with object 101 being at afirst priority, object 203 at a second priority, and object 202 at athird priority. In some embodiments, an object’s priority may be basedon the identified object. In some embodiments, an object’s priority maybe based on the object’s distance from an imaging device (also referredto as camera or capture device). According to embodiments of the presentdisclosure, based on the network bandwidth or the processing capabilityof the end client, only objects with the first, the second, or the thirdpriority may be included. In some embodiments, if only objects with asecond priority are to be included, the objects with a first prioritymay be included but the objects with the third priority may be excludedfrom the scene being transmitted or streamed.

According to an aspect of the present disclosure, the server may havethe content description in two parts: Media Presentation Description(MPD) describing the manifest of the available scenes, variousalternatives, and other characteristics; and multiple scenes withvarying assets based on either scene depth or asset priority. In anembodiment, when the end client first obtains the MPD to play any mediacontent, it may parse the MPD and learn about the various scene withvarying assets, scene timings, media-content availability, media types,various encoded alternative of the media content, minimum and maximumbandwidth supported and other content characteristics. Using thisinformation, the end client may appropriately choose which scene to berendered when and at which bandwidth availability. The end client maycontinuously measure the bandwidth fluctuations and/or processingcapability fluctuations and depending on its analysis, the end clientmay decide how to adapt to the available bandwidth by fetching analternative scene with less or more assets.

According to an aspect of the present disclosure, when the networkbandwidth and/or processing capability is limited, the server may streamassets with higher priority first than those with lower priority. Insome embodiments, assets equal to or greater than a threshold prioritymay be included and below the threshold priority may be excluded. Insome embodiments, the assets may be compressed in layer, including abase stream layer along with layers with additional details such asmaterial etc. Therefore, during times when the network bandwidth and/orprocessing capability is limited, only the base stream may be renderedand as the bandwidth increases, layers with more details may be added.In some embodiments, an asset’s priority value and/or the prioritythreshold may be defined by the server/sender and may be changed by theend client during the session or vice versa.

According to an aspect of the present disclosure, the server may have apre-defined flat background image. This pre-defined background may givethe client a pleasant viewing experience when the client’s bandwidth islimited and the end client cannot stream and/or render all assets in ascene. The background image may be updated periodically based on whatscene is being rendered. As an example, there may be a predefined 2Dbackground video which may be used when bandwidth is very limited.Therefore, when depth based adaptive streaming may be used, the scene isnot rendered completely as 3D scene but may be rendered as 2D stream.Therefore, the partial scene may be a 3D scene and partial 2D scene.

FIG. 3A illustrates a flowchart for process 300 for adaptive streamingof immersive media, according to an embodiment of the presentdisclosure.

As shown in FIG. 3A, at operation 305 a network capacity associated withan end client may be determined. As an example, a network capacityassociated with a client device may be determined by a server (which maybe a part of network 855) or a media distribution processor. In someembodiments, a processing capacity associated with the end client mayalso be determined. Based on the determined capacity associated with theend client a part of the scene to be transmitted may be determined.

At operation 310, a part of a scene to be transmitted to the end clientmay be determined based on the determined capacity associated with theend client. As an example, the server or the media distributionprocessor may determine a part of a scene to be transmitted to the endclient based on the determined capacity associated with the end client.

According to an aspect, determining the part of the scene to betransmitted may include determining a depth associated with the scene tobe transmitted based on the network capacity; and adjusting the scene tobe transmitted to include one or more first objects in the scene basedon the depth, wherein the one or more first objects are at a firstdistance within the depth. In some embodiments, it may also includeadjusting the scene to be transmitted to exclude one or more secondobjects in the scene based on the depth, wherein the one or more secondobjects are at a distance beyond the depth.

According to an aspect, determining the part of the scene to betransmitted may include determining a threshold priority associated withone or more objects in the scene to be transmitted based on the networkcapacity; and adjusting the scene to be transmitted to include one ormore first objects among the one or more objects in the scene based onthe threshold priority, wherein the one or more first objects have ahigher priority than the threshold priority. It may also includeadjusting the scene to be transmitted to exclude one or more secondobjects among the one or more objects in the scene based on thethreshold priority, wherein the one or more second objects have a lowerpriority than the threshold priority. In some embodiments, a respectiveobject priority associated with the one or more objects in the scene maybe based on a distance of a respective object from an imaging devicecapturing the scene.

According to an aspect, determining the part of the scene to betransmitted may include receiving a request for an alternative scenewith fewer objects than one or more objects in the scene from the endclient based on the network capacity associated with the end client; andadjusting the alternative scene to be transmitted to include one or morefirst objects among the one or more objects, wherein the one or morefirst objects have a higher priority than a threshold priority. It mayalso include adjusting the alternative scene to be transmitted toexclude one or more second objects among the one or more objects,wherein the one or more second objects have a lower priority than thethreshold priority. In some embodiments, the respective priorityassociated with the one or more objects in the scene may be defined bythe end client or the server.

At operation 315, a stream of immersive media associated with the scenebased on the determined part may be transmitted. In some embodiments,the stream of immersive media may be transmitted from the server or themedia distribution processor to the end client.

FIG. 3B illustrates a flowchart for process 350 for adaptive streamingof immersive media, according to an embodiment of the presentdisclosure.

As shown in FIG. 3B, at operation 355 characteristics associated with ascene to be transmitted to an end client may be determined. As anexample, characteristics associated with a scene to be transmitted to anend client may be determined by a server (which may be a part of network855) or a media distribution processor. In some embodiments, thedetermined characteristics may include image and video characteristicsan coding data associated with the immersive media stream. In someembodiments, the determined characteristics may include a depth orpriority information associated with images, videos, or scenesassociated with the immersive media stream. In some embodiments anetwork capacity/bandwidth and a processing capacity associated with theend client may also be determined. Based on the determined capacityand/or the determined characteristics of the scene to be transmitted tothe end client may be determined.

At operation 360, a part of a scene to be transmitted to the end clientmay be determined or adjusted based on the determined characteristicsassociated with the scene to be transmitted to the end client. As anexample, the server or the media distribution processor may determine atleast a part of a scene to be transmitted to the end client based on thedetermined characteristics associated with the scene to be transmittedto the end client.

According to an aspect, adjusting the part of the scene to betransmitted may include determining a depth associated with the scene tobe transmitted based on the determined characteristics associated withthe scene to be transmitted to the end client; and adjusting the sceneto be transmitted to include one or more first objects in the scenebased on the depth, wherein the one or more first objects are at a firstdistance within the depth. In some embodiments, it may also includeadjusting the scene to be transmitted to exclude one or more secondobjects in the scene based on the depth, wherein the one or more secondobjects are at a distance beyond the depth.

According to an aspect, adjusting the part of the scene to betransmitted may include determining a threshold priority associated withone or more objects in the scene to be transmitted based on thedetermined characteristics associated with the scene to be transmittedto the end client; and adjusting the scene to be transmitted to includeone or more first objects among the one or more objects in the scenebased on the threshold priority, wherein the one or more first objectshave a higher priority than the threshold priority. It may also includeadjusting the scene to be transmitted to exclude one or more secondobjects among the one or more objects in the scene based on thethreshold priority, wherein the one or more second objects have a lowerpriority than the threshold priority. In some embodiments, a respectiveobject priority associated with the one or more objects in the scene maybe based on a distance of a respective object from an imaging devicecapturing the scene.

According to an aspect, adjusting the part of the scene to betransmitted may include receiving a request for an alternative scenewith fewer objects than one or more objects in the scene from the endclient based on the determined characteristics associated with the sceneto be transmitted to the end client; and adjusting the alternative sceneto be transmitted to include one or more first objects among the one ormore objects, wherein the one or more first objects have a higherpriority than a threshold priority. It may also include adjusting thealternative scene to be transmitted to exclude one or more secondobjects among the one or more objects, wherein the one or more secondobjects have a lower priority than the threshold priority. In someembodiments, the respective priority associated with the one or moreobjects in the scene may be defined by the end client or the server.

At operation 365, an adaptive stream of immersive media associated withthe scene based on the determined part may be transmitted. In someembodiments, the stream of immersive media may be transmitted from theserver or the media distribution processor to the end client.

Although FIGS. 3A -B show example blocks of process 300 and process 350,in some implementations, process 300 and process 350 may includeadditional blocks, fewer blocks, different blocks, or differentlyarranged blocks than those depicted in FIGS. 3A-B. Additionally, oralternatively, two or more of the blocks of process 300 and process 350may be performed in parallel.

Further, the proposed methods may be implemented by processing circuitry(e.g., one or more processors or one or more integrated circuits). Inone example, the one or more processors execute a program that is storedin a non-transitory computer-readable medium to perform one or more ofthe proposed methods.

The techniques described above, can be implemented as computer softwareusing computer-readable instructions, and physically stored in one ormore computer-readable media. For example, FIG. 8 shows a computersystem 800 suitable for implementing certain embodiments of thedisclosed subject matter.

The computer software can be coded using any suitable machine code orcomputer language, that may be subject to assembly, compilation,linking, or like mechanisms to create code comprising instructions thatcan be executed directly, or through interpretation, micro-codeexecution, and the like, by computer central processing units (CPUs),Graphics Processing Units (GPUs), and the like.

The instructions can be executed on various types of computers orcomponents thereof, including, for example, personal computers, tabletcomputers, servers, smartphones, gaming devices, internet of thingsdevices, and the like.

FIG. 4 illustrates a simplified block diagram of a communication system400 according to an embodiment of the present disclosure. Thecommunication system 400 may include at least two terminals 410-420interconnected via a network 450. For unidirectional transmission ofdata, a first terminal 410 may code video data at a local location fortransmission to the other terminal 420 via the network 450. The secondterminal 420 may receive the coded video data of the other terminal fromthe network 450, decode the coded data, and display the recovered videodata. Unidirectional data transmission may be common in media servingapplications and the like.

FIG. 4 illustrates a second pair of terminals 430, 440 provided tosupport bidirectional transmission of coded video that may occur, forexample, during videoconferencing. For bidirectional transmission ofdata, each terminal 430, 440 may code video data captured at a locallocation for transmission to the other terminal via the network 450.Each terminal 430, 440 also may receive the coded video data transmittedby the other terminal, may decode the coded data and may display therecovered video data at a local display device.

In FIG. 4 , the terminals 410-440 may be illustrated as servers,personal computers and smart phones but the principles of the presentdisclosure are not so limited. Embodiments of the present disclosurefind application with laptop computers, tablet computers, media playersand/or dedicated video conferencing equipment. The network 450represents any number of networks that convey coded video data among theterminals 410-440, including for example wireline and/or wirelesscommunication networks. The communication network 450 may exchange datain circuit-switched and/or packet-switched channels. Representativenetworks include telecommunications networks, local area networks, widearea networks, and/or the Internet. For the purposes of the presentdiscussion, the architecture and topology of the network 450 may beimmaterial to the operation of the present disclosure unless explainedherein below.

FIG. 5 illustrates, as an example for an application for the disclosedsubject matter, the placement of a video encoder and decoder in astreaming environment, for example streaming system 500. The disclosedsubject matter can be equally applicable to other video enabledapplications, including, for example, video conferencing, digital TV,storing of compressed video on digital media including CD, DVD, memorystick and the like, and so on.

A streaming system may include a capture subsystem 513, which caninclude a video source 501, for example a digital camera, creating, forexample, an uncompressed video sample stream 502. That sample stream502, depicted as a bold line to emphasize a high data volume whencompared to encoded video bitstreams, can be processed by an encoder 503coupled to the video source 501, which may be for example a camera. Theencoder 503 can include hardware, software, or a combination thereof toenable or implement aspects of the disclosed subject matter as describedin more detail below. The encoded video bitstream 504, depicted as athin line to emphasize the lower data volume when compared to the samplestream, can be stored on a streaming server 505 for future use. One ormore streaming clients 506, 508 can access the streaming server 505 toretrieve copies, for example video bitstream 507 and video bitstream509, of the encoded video bitstream 504. A client 506 can include avideo decoder 510, which decodes the incoming copy of the encoded videobitstream 507 and creates an outgoing video sample stream 511 that canbe rendered on a display 512 or other rendering device not depicted. Insome streaming systems, the video bitstreams 504, 507, 509 can beencoded according to certain video coding/compression standards.Examples of those standards include ITU-T Recommendation H.265. Underdevelopment is a video coding standard informally known as VersatileVideo Coding (VVC). The disclosed subject matter may be used in thecontext of VVC.

FIG. 6 may be a functional block diagram of a video decoder 510according to an embodiment.

A receiver 610 may receive one or more codec video sequences to bedecoded by the decoder 510; in the same or another embodiment, one codedvideo sequence at a time, where the decoding of each coded videosequence is independent from other coded video sequences. The codedvideo sequence may be received from a channel 612, which may be ahardware/software link to a storage device, that stores the encodedvideo data. The receiver 610 may receive the encoded video data withother data, for example, coded audio data, and/or ancillary datastreams, that may be forwarded to their respective using entities notdepicted. The receiver 610 may separate the coded video sequence fromthe other data. To combat network jitter, a buffer 615, which may be forexample a buffer memory, may be coupled in between receiver 610 andentropy decoder / parser 620 “parser” henceforth. When receiver 610 isreceiving data from a store/forward device of sufficient bandwidth andcontrollability, or from an isosynchronous network, the buffer 615 maynot be needed, or can be small. For use on best effort packet networkssuch as the Internet, the buffer 615 may be required, can becomparatively large, and can advantageously of adaptive size.

The video decoder 510 may include a parser 620 to reconstruct symbols621 from the entropy coded video sequence. Categories of those symbolsinclude information used to manage operation of the decoder 510, andpotentially information to control a rendering device such as a display512 that is not an integral part of the decoder but can be coupled toit, as was shown in FIG. 6 . The control information for the renderingdevice(s may be in the form of Supplementary Enhancement Information SEImessages or Video Usability Information (VUI) parameter set fragmentsnot depicted. The parser 620 may parse / entropy-decode the coded videosequence received. The coding of the coded video sequence can be inaccordance with a video coding technology or standard, and can followprinciples well known to a person skilled in the art, including variablelength coding, Huffman coding, arithmetic coding with or without contextsensitivity, and so forth. The parser 620 may extract from the codedvideo sequence, a set of subgroup parameters for at least one of thesubgroups of pixels in the video decoder, based upon at least oneparameters corresponding to the group. Subgroups can include Groups ofPictures GOPs, pictures, tiles, slices, macroblocks, Coding Units CUs,blocks, Transform Units TUs, Prediction Units PUs and so forth. Theentropy decoder / parser may also extract from the coded video sequenceinformation such as transform coefficients, quantizer parameter QPvalues, motion vectors, and so forth.

The parser 620 may perform entropy decoding / parsing operation on thevideo sequence received from the buffer 615, so to create symbols 621.The parser 620 may receive encoded data, and selectively decodeparticular symbols 621. Further, the parser 620 may determine whetherthe particular symbols 621 are to be provided to a Motion CompensationPrediction unit 653, a scaler / inverse transform unit 651, an IntraPrediction Unit 652, or a loop filter 656.

Reconstruction of the symbols 621 can involve multiple different unitsdepending on the type of the coded video picture or parts thereof suchas inter and intra picture, inter and intra block, and other factors.Which units are involved, and how, can be controlled by the subgroupcontrol information that was parsed from the coded video sequence by theparser 620. The flow of such subgroup control information between theparser 620 and the multiple units below is not depicted for clarity.

Beyond the functional blocks already mentioned, decoder 510 can beconceptually subdivided into a number of functional units as describedbelow. In a practical implementation operating under commercialconstraints, many of these units interact closely with each other andcan, at least partly, be integrated into each other. However, fordescribing the disclosed subject matter, the conceptual subdivision intothe functional units below is appropriate.

A first unit is the scaler / inverse transform unit 651. The scaler /inverse transform unit 651 receives quantized transform coefficient aswell as control information, including which transform to use, blocksize, quantization factor, quantization scaling matrices, etc. assymbol(s 621 from the parser 620. It can output blocks comprising samplevalues that can be input into aggregator 655.

In some cases, the output samples of the scaler / inverse transform unit651 can pertain to an intra coded block; that is: a block that is notusing predictive information from previously reconstructed pictures, butcan use predictive information from previously reconstructed parts ofthe current picture. An intra picture prediction unit 652 can providesuch predictive information. In some cases, the intra picture predictionunit 652 generates a block of the same size and shape of the block underreconstruction, using surrounding already reconstructed informationfetched from the current partly reconstructed picture 658. Theaggregator 655, in some cases, adds, on a per sample basis, theprediction information the intra prediction unit 652 has generated tothe output sample information as provided by the scaler / inversetransform unit 651.

In other cases, the output samples of the scaler / inverse transformunit 651 can pertain to an inter coded, and potentially motioncompensated block. In such a case, a Motion Compensation Prediction unit653 can access reference picture memory 657 to fetch samples used forprediction. After motion compensating the fetched samples in accordancewith the symbols, the aggregator 655 to the output of the scaler /inverse can add 621 pertaining to the block, these samples transformunit in this case called the residual samples or residual signal so togenerate output sample information. The addresses within the referencepicture memory form where the motion compensation unit fetchesprediction samples can be controlled by motion vectors, available to themotion compensation unit in the form of symbols 621 that can have, forexample X, Y, and reference picture components. Motion compensation alsocan include interpolation of sample values as fetched from the referencepicture memory when sub-sample exact motion vectors are in use, motionvector prediction mechanisms, and so forth.

The output samples of the aggregator 655 can be subject to variousloop-filtering techniques in the loop filter unit 656. Video compressiontechnologies can include in-loop filter technologies that are controlledby parameters included in the coded video bitstream and made availableto the loop filter unit 656 as symbols 621 from the parser 620, but canalso be responsive to meta-information obtained during the decoding ofprevious in decoding order parts of the coded picture or coded videosequence, as well as responsive to previously reconstructed andloop-filtered sample values.

The output of the loop filter unit 656 can be a sample stream that canbe output to the render device 512 as well as stored in the referencepicture memory 657 for use in future inter-picture prediction.

Certain coded pictures, once fully reconstructed, can be used asreference pictures for future prediction. Once a coded picture is fullyreconstructed and the coded picture has been identified as a referencepicture by, for example, parser 620), the current reference picture 658can become part of the reference picture buffer 657, and a fresh currentpicture memory can be reallocated before commencing the reconstructionof the following coded picture.

The video decoder 510 may perform decoding operations according to apredetermined video compression technology that may be documented in astandard, such as ITU-T Rec. H.265. The coded video sequence may conformto a syntax specified by the video compression technology or standardbeing used, in the sense that it adheres to the syntax of the videocompression technology or standard, as specified in the videocompression technology document or standard and specifically in theprofiles document therein. Also necessary for compliance can be that thecomplexity of the coded video sequence is within bounds as defined bythe level of the video compression technology or standard. In somecases, levels restrict the maximum picture size, maximum frame rate,maximum reconstruction sample rate measured in, for example mega samplesper second, maximum reference picture size, and so on. Limits set bylevels can, in some cases, be further restricted through HypotheticalReference Decoder (HRD) specifications and metadata for HRD buffermanagement signaled in the coded video sequence.

In an embodiment, the receiver 610 may receive additional redundant datawith the encoded video. The additional data may be included as part ofthe coded video sequence(s. The additional data may be used by the videodecoder 510 to properly decode the data and/or to more accuratelyreconstruct the original video data. Additional data can be in the formof, for example, temporal, spatial, or signal-to-noise ratio SNRenhancement layers, redundant slices, redundant pictures, forward errorcorrection codes, and so on.

FIG. 7 may be a functional block diagram of a video encoder 503according to an embodiment of the present disclosure.

The encoder 503 may receive video samples from a video source 501 thatis not part of the encoder that may capture video images to be coded bythe encoder 503.

The video source 501 may provide the source video sequence to be codedby the encoder 503 in the form of a digital video sample stream that canbe of any suitable bit depth for example: 8 bit, 10 bit, 12 bit, ...,any colorspace for example, BT.601 Y CrCB, RGB, ... and any suitablesampling structure for example Y CrCb 4:2:0, Y CrCb 4:4:4. In a mediaserving system, the video source 501 may be a storage device storingpreviously prepared video. In a videoconferencing system, the videosource 501 may be a camera that captures local image information as avideo sequence. Video data may be provided as a plurality of individualpictures that impart motion when viewed in sequence. The picturesthemselves may be organized as a spatial array of pixels, wherein eachpixel can comprise one or more samples depending on the samplingstructure, color space, etc. in use. A person skilled in the art canreadily understand the relationship between pixels and samples. Thedescription below focuses on samples.

According to an embodiment, the encoder 503 may code and compress thepictures of the source video sequence into a coded video sequence 743 inreal time or under any other time constraints as required by theapplication. Enforcing appropriate coding speed is one function ofController 750. Controller controls other functional units as describedbelow and is functionally coupled to these units. The coupling is notdepicted for clarity. Parameters set by controller can include ratecontrol related parameters picture skip, quantizer, lambda value ofrate-distortion optimization techniques, ..., picture size, group ofpictures GOP layout, maximum motion vector search range, and so forth. Aperson skilled in the art can readily identify other functions ofcontroller 750 as they may pertain to video encoder 503 optimized for acertain system design.

Some video encoders operate in what a person skilled in the art readilyrecognizes as a “coding loop.” As an oversimplified description, acoding loop can consist of the encoding part of an encoder 730 “sourcecoder” henceforth responsible for creating symbols based on an inputpicture to be coded, and a reference picture(s), and a local decoder 733embedded in the encoder 503 that reconstructs the symbols to create thesample data that a remote decoder also would create as any compressionbetween symbols and coded video bitstream is lossless in the videocompression technologies considered in the disclosed subject matter.That reconstructed sample stream is input to the reference picturememory 734. As the decoding of a symbol stream leads to bit-exactresults independent of decoder location local or remote, the referencepicture buffer content is also bit exact between local encoder andremote encoder. In other words, the prediction part of an encoder “sees”as reference picture samples exactly the same sample values as a decoderwould “see” when using prediction during decoding. This fundamentalprinciple of reference picture synchronicity and resulting drift, ifsynchronicity cannot be maintained, for example because of channelerrors is well known to a person skilled in the art.

The operation of the “local” decoder 733 can be the same as of a“remote” decoder 510, which has already been described in detail abovein conjunction with FIG. 6 . Briefly referring also to FIG. 7 , however,as symbols are available and en/decoding of symbols to a coded videosequence by entropy coder 745 and parser 620 can be lossless, theentropy decoding parts of decoder 510, including channel 612, receiver610, buffer 615, and parser 620 may not be fully implemented in localdecoder 733.

An observation that can be made at this point is that any decodertechnology except the parsing/entropy decoding that is present in adecoder also necessarily needs to be present, in substantially identicalfunctional form, in a corresponding encoder. The description of encodertechnologies can be abbreviated as they are the inverse of thecomprehensively described decoder technologies. Only in certain areas amore detail description is required and provided below.

As part of its operation, the source coder 730 may perform motioncompensated predictive coding, which codes an input frame predictivelywith reference to one or more previously-coded frames from the videosequence that were designated as “reference frames.” In this manner, thecoding engine 732 codes differences between pixel blocks of an inputframe and pixel blocks of reference frame(s that may be selected asprediction reference(s to the input frame.

The local video decoder 733 may decode coded video data of frames thatmay be designated as reference frames, based on symbols created by thesource coder 730. Operations of the coding engine 732 may advantageouslybe lossy processes. When the coded video data may be decoded at a videodecoder not shown in FIG. 7 , the reconstructed video sequence typicallymay be a replica of the source video sequence with some errors. Thelocal video decoder 733 replicates decoding processes that may beperformed by the video decoder on reference frames and may causereconstructed reference frames to be stored in the reference picturecache 734. In this manner, the encoder 503 may store copies ofreconstructed reference frames locally that have common content as thereconstructed reference frames that will be obtained by a far-end videodecoder absent transmission errors.

The predictor 735 may perform prediction searches for the coding engine732. That is, for a new frame to be coded, the predictor 735 may searchthe reference picture memory 734 for sample data as candidate referencepixel blocks or certain metadata such as reference picture motionvectors, block shapes, and so on, that may serve as an appropriateprediction reference for the new pictures. The predictor 735 may operateon a sample block-by-pixel block basis to find appropriate predictionreferences. In some cases, as determined by search results obtained bythe predictor 735, an input picture may have prediction references drawnfrom multiple reference pictures stored in the reference picture memory734.

The controller 750 may manage coding operations of the video coder 730,including, for example, setting of parameters and subgroup parametersused for encoding the video data.

Output of all aforementioned functional units may be subjected toentropy coding in the entropy coder 745. The entropy coder translatesthe symbols as generated by the various functional units into a codedvideo sequence, by loss-less compressing the symbols according totechnologies known to a person skilled in the art as, for exampleHuffman coding, variable length coding, arithmetic coding, and so forth.

The transmitter 740 may buffer the coded video sequence(s as created bythe entropy coder 745 to prepare it for transmission via a communicationchannel 760, which may be a hardware/software link to a storage devicewhich would store the encoded video data. The transmitter 740 may mergecoded video data from the video coder 730 with other data to betransmitted, for example, coded audio data and/or ancillary data streamssources not shown.

The controller 750 may manage operation of the encoder 503. Duringcoding, the controller 750 may assign to each coded picture a certaincoded picture type, which may affect the coding techniques that may beapplied to the respective picture. For example, pictures often may beassigned as one of the following frame types:

An Intra Picture I picture may be one that may be coded and decodedwithout using any other frame in the sequence as a source of prediction.Some video codecs allow for different types of Intra pictures,including, for example Independent Decoder Refresh Pictures. A personskilled in the art is aware of those variants of I pictures and theirrespective applications and features.

A Predictive picture P picture may be one that may be coded and decodedusing intra prediction or inter prediction using at most one motionvector and reference index to predict the sample values of each block.

A Bi-directionally Predictive Picture B Picture may be one that may becoded and decoded using intra prediction or inter prediction using atmost two motion vectors and reference indices to predict the samplevalues of each block. Similarly, multiple-predictive pictures can usemore than two reference pictures and associated metadata for thereconstruction of a single block.

Source pictures commonly may be subdivided spatially into a plurality ofsample blocks for example, blocks of 4 × 4, 8 × 8, 4 × 8, or 16 × 16samples each and coded on a block-by-block basis. Blocks may be codedpredictively with reference to other already coded blocks as determinedby the coding assignment applied to the blocks’ respective pictures. Forexample, blocks of I pictures may be coded non-predictively or they maybe coded predictively with reference to already coded blocks of the samepicture spatial prediction or intra prediction. Pixel blocks of Ppictures may be coded non-predictively, via spatial prediction or viatemporal prediction with reference to one previously coded referencepictures. Blocks of B pictures may be coded non-predictively, viaspatial prediction or via temporal prediction with reference to one ortwo previously coded reference pictures.

The video encoder 503 may perform coding operations according to apredetermined video coding technology or standard, such as ITU-T Rec.H.265. In its operation, the video encoder 503 may perform variouscompression operations, including predictive coding operations thatexploit temporal and spatial redundancies in the input video sequence.The coded video data, therefore, may conform to a syntax specified bythe video coding technology or standard being used.

In an embodiment, the transmitter 740 may transmit additional data withthe encoded video. The video coder 730 may include such data as part ofthe coded video sequence. Additional data may comprisetemporal/spatial/SNR enhancement layers, other forms of redundant datasuch as redundant pictures and slices, Supplementary EnhancementInformation (SEI) messages, Visual Usability Information (VUI) parameterset fragments, and so on.

The components shown in FIG. 8 for computer system 800 are exemplary innature and are not intended to suggest any limitation as to the scope ofuse or functionality of the computer software implementing embodimentsof the present disclosure. Neither should the configuration ofcomponents be interpreted as having any dependency or requirementrelating to any one or combination of components illustrated in theexemplary embodiment of a computer system 800.

Computer system 800 may include certain human interface input devices.Such a human interface input device may be responsive to input by one ormore human users through, for example, tactile input (such as:keystrokes, swipes, data glove movements), audio input (such as: voice,clapping), visual input (such as: gestures), olfactory input (notdepicted). The human interface devices can also be used to capturecertain media not necessarily directly related to conscious input by ahuman, such as audio (such as: speech, music, ambient sound), images(such as: scanned images, photographic images obtain from a still imagecamera), video (such as two-dimensional video, three-dimensional videoincluding stereoscopic video).

Input human interface devices may include one or more of (only one ofeach depicted): keyboard 801, mouse 802, trackpad 803, touch screen 810,joystick 805, microphone 806, scanner 807, camera 808.

Computer system 800 may also include certain human interface outputdevices. Such human interface output devices may be stimulating thesenses of one or more human users through, for example, tactile output,sound, light, and smell/taste. Such human interface output devices mayinclude tactile output devices (for example tactile feedback by thetouch screen 810, data-glove 1204, or joystick 805, but there can alsobe tactile feedback devices that do not serve as input devices), audiooutput devices (such as: speakers 809, headphones (not depicted)),visual output devices (such as screens 810 to include cathode ray tube(CRT) screens, liquid-crystal display (LCD) screens, plasma screens,organic light-emitting diode (OLED) screens, each with or withouttouch-screen input capability, each with or without tactile feedbackcapability—some of which may be capable to output two dimensional visualoutput or more than three dimensional output through means such asstereographic output; virtual-reality glasses (not depicted),holographic displays and smoke tanks (not depicted)), and printers (notdepicted).

Computer system 800 can also include human accessible storage devicesand their associated media such as optical media including CD/DVD ROM/RW820 with CD/DVD or the like media 821, thumb-drive 822, removable harddrive or solid state drive 823, legacy magnetic media such as tape andfloppy disc (not depicted), specialized ROM/ASIC/PLD based devices suchas security dongles (not depicted), and the like.

Those skilled in the art should also understand that term “computerreadable media” as used in connection with the presently disclosedsubject matter does not encompass transmission media, carrier waves, orother transitory signals.

Computer system 800 can also include interface to one or morecommunication networks 855. Networks 855 can for example be wireless,wireline, optical. Networks 855 can further be local, wide-area,metropolitan, vehicular and industrial, real-time, delay-tolerant, andso on. Examples of networks 855 include local area networks such asEthernet, wireless LANs, cellular networks to include GSM, 3G, 4G, 5G,LTE and the like, TV wireline or wireless wide area digital networks toinclude cable TV, satellite TV, and terrestrial broadcast TV, vehicularand industrial to include CANBus, and so forth. Certain networks 855commonly require external network interface adapters 854) that attachedto certain general purpose data ports or peripheral buses 849 (such as,for example USB ports of the computer system 800; others are commonlyintegrated into the core of the computer system 800 by attachment to asystem bus as described below (for example Ethernet interface into a PCcomputer system or cellular network interface into a smartphone computersystem). Using any of these networks 855, computer system 800 cancommunicate with other entities. Such communication can beuni-directional, receive only (for example, broadcast TV),uni-directional send-only (for example CANbus to certain CANbusdevices), or bi-directional, for example to other computer systems usinglocal or wide area digital networks. Certain protocols and protocolstacks can be used on each of those networks 855 and network interfaces854 as described above.

Aforementioned human interface devices, human-accessible storagedevices, and network interfaces can be attached to a core 840 of thecomputer system 800.

The core 840 can include one or more Central Processing Units (CPU) 841,Graphics Processing Units (GPU) 842, specialized programmable processingunits in the form of Field Programmable Gate Areas (FPGA) 843, hardwareaccelerators for certain tasks, for example accelerator 844, and soforth. These devices, along with Read-only memory (ROM) 845,Random-access memory (RAM) 846, internal mass storage such as internalnon-user accessible hard drives, solid-state drives (SSDs), and the like847, may be connected through a system bus 899. In some computersystems, the system bus 899 can be accessible in the form of one or morephysical plugs to enable extensions by additional CPUs, GPU, and thelike. The peripheral devices can be attached either directly to thecore’s system bus 899, or through a peripheral bus 849. Architecturesfor a peripheral bus include peripheral component interconnect (PCI),USB, and the like.

CPUs 841, GPUs 842, FPGAs 843, and accelerators 844 can execute certaininstructions that, in combination, can make up the aforementionedcomputer code. That computer code can be stored in ROM 845 or RAM 846.Transitional data can be also be stored in RAM 846, whereas permanentdata can be stored for example, in the internal mass storage 847. Faststorage and retrieve to any of the memory devices can be enabled throughthe use of cache memory, that can be closely associated with one or moreCPU 841, GPU 842, mass storage 847, ROM 845, RAM 846, and the like.

The computer readable media can have computer code thereon forperforming various computer-implemented operations. The media andcomputer code can be those specially designed and constructed for thepurposes of the present disclosure, or they can be of the kind wellknown and available to those having skill in the computer software arts.

As an example and not by way of limitation, the computer system havingarchitecture 800, and specifically the core 840 can providefunctionality as a result of processor(s) (including CPUs, GPUs, FPGA,accelerators, and the like) executing software embodied in one or moretangible, computer-readable media. Such computer-readable media can bemedia associated with user-accessible mass storage as introduced above,as well as certain storage of the core 840 that are of non-transitorynature, such as core-internal mass storage 847 or ROM 845. The softwareimplementing various embodiments of the present disclosure can be storedin such devices and executed by core 840. A computer-readable medium caninclude one or more memory devices or chips, according to particularneeds. The software can cause the core 840 and specifically theprocessors therein (including CPU, GPU, FPGA, and the like) to executeparticular processes or particular parts of particular processesdescribed herein, including defining data structures stored in RAM 846and modifying such data structures according to the processes defined bythe software. In addition or as an alternative, the computer system canprovide functionality as a result of logic hardwired or otherwiseembodied in a circuit (for example: accelerator 844), which can operatein place of or together with software to execute particular processes orparticular parts of particular processes described herein. Reference tosoftware can encompass logic, and vice versa, where appropriate.Reference to a computer-readable media can encompass a circuit (such asan integrated circuit (IC)) storing software for execution, a circuitembodying logic for execution, or both, where appropriate. The presentdisclosure encompasses any suitable combination of hardware andsoftware.

While this disclosure has described several exemplary embodiments, thereare alterations, permutations, and various substitute equivalents, whichfall within the scope of the disclosure. It will thus be appreciatedthat those skilled in the art will be able to devise numerous systemsand methods which, although not explicitly shown or described herein,embody the principles of the disclosure and are thus within the spiritand scope thereof.

What is claimed is:
 1. A method for adaptive streaming of lightfield orholographic immersive media, the method being executed by one or moreprocessors, the method comprising: determining characteristicsassociated with a scene to be transmitted to an end client; based on thedetermined characteristics, adjusting at least a part of the scene to betransmitted to the end client; and transmitting an adaptive stream ofthe lightfield or the holographic immersive media comprising theadjusted scene based on the determined characteristics.
 2. The method ofclaim 1, wherein adjusting at least the part of the scene to betransmitted comprises: determining a depth associated with the scene tobe transmitted based on the determined characteristics; and adjustingthe scene to be transmitted to include one or more first objects in thescene based on the depth, wherein the one or more first objects are at afirst distance within the depth.
 3. The method of claim 2, whereinadjusting at least the part of the scene to be transmitted furthercomprises: adjusting the scene to be transmitted to exclude one or moresecond objects in the scene based on the depth, wherein the one or moresecond objects are at a distance beyond the depth.
 4. The method ofclaim 1, wherein adjusting at least the part of the scene to betransmitted comprises: determining a threshold priority associated withone or more objects in the scene to be transmitted based on thedetermined characteristics; and adjusting the scene to be transmitted toinclude one or more first objects among the one or more objects in thescene based on the threshold priority, wherein the one or more firstobjects have a higher priority than the threshold priority.
 5. Themethod of claim 4, wherein adjusting at least the part of the scene tobe transmitted further comprises: adjusting the scene to be transmittedto exclude one or more second objects among the one or more objects inthe scene based on the threshold priority, wherein the one or moresecond objects have a lower priority than the threshold priority.
 6. Themethod of claim 5, wherein a respective object priority associated withthe one or more objects in the scene is based on a distance of arespective object from an imaging device capturing the scene.
 7. Themethod of claim 1, wherein adjusting at least the part of the scene tobe transmitted comprises: receiving a request for an alternative scenewith fewer objects than one or more objects in the scene from the endclient based on the determined characteristics associated with the endclient; and adjusting the alternative scene to be transmitted to includeone or more first objects among the one or more objects, wherein the oneor more first objects have a higher priority than a threshold priority.8. The method of claim 7, wherein adjusting at least the part of thescene to be transmitted further comprises: adjusting the alternativescene to be transmitted to exclude one or more second objects among theone or more objects, wherein the one or more second objects have a lowerpriority than the threshold priority.
 9. The method of claim 8, whereina respective priority associated with the one or more objects in thescene is defined by the end client.
 10. An apparatus for adaptivestreaming of lightfield or holographic immersive media, the apparatuscomprising: at least one memory configured to store program code; and atleast one processor configured to read the program code and operate asinstructed by the program code, the program code including: firstdetermining code configured to cause the at least one processor todetermine characteristics associated with a scene to be transmitted toan end client; second determining code configured to cause the at leastone processor to adjust at least a part of the scene to be transmittedto the end client based on the determined characteristics; andtransmitting code configured to cause the at least one processor totransmit an adaptive stream of the lightfield or the holographicimmersive media comprising the adjusted scene based on the determinedcharacteristics.
 11. The apparatus of claim 10, wherein the seconddetermining code comprises: third determining code configured to causethe at least one processor to determine a depth associated with thescene to be transmitted based on the determined characteristics; andfirst adjusting code configured to cause the at least one processor toadjust the scene to be transmitted to include one or more first objectsin the scene based on the depth, wherein the one or more first objectsare at a first distance within the depth.
 12. The apparatus of claim 11,wherein the second determining code further comprises: second adjustingcode configured to cause the at least one processor to adjust the sceneto be transmitted to exclude one or more second objects in the scenebased on the depth, wherein the one or more second objects are at adistance beyond the depth.
 13. The apparatus of claim 10, wherein thesecond determining code comprises: fourth determining code configured tocause the at least one processor to determine a threshold priorityassociated with one or more objects in the scene to be transmitted basedon the determined characteristics; and third adjusting code configuredto cause the at least one processor to adjust the scene to betransmitted to include one or more first objects among the one or moreobjects in the scene based on the threshold priority, wherein the one ormore first objects have a higher priority than the threshold priority.14. The apparatus of claim 13, wherein the second determining codefurther comprises: fourth adjusting code configured to cause the atleast one processor to adjust the scene to be transmitted to exclude oneor more second objects among the one or more objects in the scene basedon the threshold priority, wherein the one or more second objects have alower priority than the threshold priority.
 15. The apparatus of claim14, wherein a respective object priority associated with the one or moreobjects in the scene is based on a distance of a respective object froman imaging device capturing the scene.
 16. A non-transitorycomputer-readable medium storing instructions, the instructionscomprising: one or more instructions that, when executed by one or moreprocessors of a device for adaptive streaming of lightfield orholographic immersive media, cause the one or more processors to:determine characteristics associated with a scene to be transmitted toan end client; based on the determined characteristics associated withthe end client, adjust at least a part of the scene to be transmitted tothe end client; and transmit an adaptive stream of the lightfield or theholographic immersive media comprising the adjusted scene based on thedetermined characteristics.
 17. The non-transitory computer-readablemedium of claim 16, wherein adjusting at least the part of the scene tobe transmitted comprises: determining a depth associated with the sceneto be transmitted based on the determined characteristics; and adjustingthe scene to be transmitted to include one or more first objects in thescene based on the depth, wherein the one or more first objects are at afirst distance within the depth.
 18. The non-transitorycomputer-readable medium of claim 17, wherein adjusting at least thepart of the scene to be transmitted further comprises: adjusting thescene to be transmitted to exclude one or more second objects in thescene based on the depth, wherein the one or more second objects are ata distance beyond the depth.
 19. The non-transitory computer-readablemedium of claim 16, wherein adjusting at least the part of the scene tobe transmitted comprises: determining a threshold priority associatedwith one or more objects in the scene to be transmitted based on thedetermined characteristics; and adjusting the scene to be transmitted toinclude one or more first objects among the one or more objects in thescene based on the threshold priority, wherein the one or more firstobjects have a higher priority than the threshold priority.
 20. Thenon-transitory computer-readable medium of claim 19, wherein adjustingat least the part of the scene to be transmitted further comprises:adjusting the scene to be transmitted to exclude one or more secondobjects among the one or more objects in the scene based on thethreshold priority, wherein the one or more second objects have a lowerpriority than the threshold priority.